A batch process may perform a list of commands. It may be run by a computer's operating system using a batch file, or may be executed within a program using a macro or internal scripting tool. A program takes a set of data files as input, processes the data, and produces a set of output data files. This operating environment is termed as “batch processing” because the input data are collected into batches on files and are processed in batches by the program.
An example of batch processing is the way that credit card companies process their billing. A customer does not receive a bill for each separate credit card purchase transaction, but rather one monthly bill for all of that month's purchases. The bill is created through batch processing, where all of the data are collected and held until the bill is processed as a batch at the end of a billing cycle.